The study design is that of a prospective cohort study in which 200 smoking participants will be recruited from an existing HIV-seropositive cohort of 800 patients (the Human Oral Papillomavirus Etiology (HOPE) Study). Participants will be enrolled from the Johns Hopkins HIV (Moore) Clinic and the resources of the Johns Hopkins Adult Outpatient General Clinical Research Center (GCRC) and pilot project funding from the Lung Cancer SPORE will be utilized to fund the costs of the CT scans. An interdisciplinary team with expertise in HIV-associated malignancy, CT screening, lung cancer surgery, HIV infection, epidemiology and biostatistics has been assembled to test the hypothesis by accomplishing the following Specific Aims: